Cope.] 490 [Sept. 17, 



Size medium ; fourth upper premolor equilateral ; all cusps acute ; true 



molars .0165 M. suhtrigonits. 



aa.a. Cusps of last premolars compressed in lower jaw. 



Least. Second and third lower true molars subequal ; cusps, especially 

 the internal, elevated ; anterior inner confluent into an edge ; true 

 molars, . 013 M. angustus. 



Largest ; cusps of inferior molars obtuse ; P-m. Ill .008, its heel short 

 and small M. mandibular is. 



Medium ; last inferior molar larger than penultimate ; true molars, .014 ; 

 P-m. Ill .006 Anisonchus sectorius. 



Of M. turgidus there are two specimens ; and of M. siibtrigonus, M. an- 

 gustus and 31. mandibularis one each. 



In the M. turgidus there are no cingula on the fourth premolar. It is 

 wider than long, and the external face is a little flattened. The tubercles 

 are conic ; the external has a small one at the anterior base, and a rudi- 

 ment at the posterior base, and there is a low one on the posterior side at 

 the middle. The second true molar is wider than the first. The tubercles 

 are all round in section. Besides those already mentioned, there is a rudi- 

 ment of a posterior inner on the first, which is represented by a cingulum 

 on the second. The latter has basal cingula all around except on the inner 

 side ; the same are visible on the first true molar in a rudimental condition. 

 Enamel nearly smooth. 



The inferior molars are of robust proportions. Their sizes are, commenc- 

 ing with the largest : P-m. IV ; M. II ; M. I ; M. III. The last molar is 

 only half as large as the penultimate. It has two anterior and an external 

 lateral tubercles, and a heel. On the penultimate molar, there are two an- 

 terior tubercles with a trace of anterior inner ; also a broad flat heel, with 

 a low tubercle on the external side. The constitution of the firet true mo- 

 lar is identical. The fourth premolar has a rudimental heel consisting of 

 a low tubercle only. The principal cusp is conic and is over the middle 

 of the transA^erse diameter, and a little behind the middle of the antero- 

 posterior diameter. No cingula. Enamel nearly smooth. 



Measurements. M. 



Maxillary bone. 

 Length of base of P-m. lY, M. I and M. II 0175 



_. , ^ ^^_ c anteroposterior 0055 



Diameters base Pm. 1 V < , r.i^n- 



( transverse 006o 



Diameters base M. I 



anteroposterior 0060 



transverse 0070 



.r^. , ,^ ^^ (anteroposterior 0060 



Diameters base M. 11 I ^ „„„_ 



( transverse 0095 



Mandible. 



Length of bases of last four molars 0250 



T^. , T-> T-rx (anteroposterior 0070 



Diameters P-m. IV \ , rvnrr- 



( transverse 0055 



